Question

The S.I. unit of decay constant is:

• A. metre
• B. hertz
• C. per metre
• D. metre (repeated)

Hint:

Decay constant indicates the probability of decay per unit time.

Answer 1

The Correct Option is B

The decay constant \( \lambda \) represents the probability per unit time that a nucleus will decay. Therefore, its unit is the reciprocal of time. In the SI system, this is expressed as: \[ [\lambda] = \text{s}^{-1}, \] which is also equivalent to hertz (Hz), the unit of frequency. This reflects the fact that decay is a stochastic process characterized by a rate of events per second.